DHT11 reading wrong data with ESPHome

ESPHome
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1

Hello Everyone!
I have used the dht11 and dht22 sensors for a while now and in the beginning everything was working perfectly fine. A few months ago, i noticed that one of the temperature sensors (dht11) started giving out wrong data, since my living room humidity can not be 80%.
I tried multiple things like switching from a raspberry pi running ESPHome to an esp32. I also tried setting the type of sensor in the config.
I don’t know what I can do to fix this. I also wasn’t able to find anything similar online.

This is the config I am using right now:

sensor:
  - platform: dht
    pin: GPIO15
    humidity:
      name: "Feuchtigkeit"
    temperature:
      name: "Temperatur"
    update_interval: 30s

These are the sensor readings:

grafik
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The temperature seems like it is the right value, so i dont see any problems with that!

Has anyone had the same or a similar issue and how did you fix it?
If anyone has any ideas, please share them with me since I am a little desperate right now!

2

Yes it can, but would be noticeably humid.
You need to verify your Esphome log. If you get wrong readings there also, there’s nothing you can do than getting new sensor.

3

Did you try replacing the sensor?

They do go bad. Well bader in the case of the DHT11.

4

Have you tried setting the model to dht11? Had issues with mine that needed manually setting, but that was a dht22.

5

Those are both known to be less than great sensors and to go bad over time. If you care, get better sensors. These might help (if you have the time, they are interesting to read, tldr; the dht11 is not great and doesn’t last):

1 Like
6

DHT22 is ok for indoor home use. I use a lot of them without issue. They are not suitable for outdoor use.

After reading that first article I tried some SHT3x sensors from Alliexpress. They were worse than the DHT22s. Must have received some factory rejects.

I have also read about people receiving counterfeit DHT22s.

So it is not just important what you buy but where you buy it from too.

7

That’s the probable case.
Sensirion manufactures sensor 4x. The best units are labeled 45, less accurate ones are labeled 41 and least accurate ones 40. Units that don’t pass these control levels are disposed …or maybe sold in aliexpress.

8

I already tried replacing the sensor. It didnt change anything…

9

Yes, I did. It didnt change anything…

10

Thanks! I’ll give that a look!

11

Post your esphome log.

12

I might give these another try. I found my old purchases, they were SHT31D.

I use a TMP117 as my temperature test reference.

13

I mean best of 4x gen. Equally SHT35, 31, 30, …aliexpress :wink:

14

SHT85 seems to be the gold standard from those tests above. Not cheap though.

15

Yep 75 and 85 are special sensors that they use for evaluation boards.
I have one, no practical difference, except price and pin header…

If you are not looking for best possible humidity accuracy, SHT30/31 is very ok.

Edit:
I have been using many Sensirion sensors under very harsh environments, like in 70-90% CO2 atmosfere and the best performer has been SHT21. The one that got hurted most quicly was 75.